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1.
Is Visually Guided Reaching in Early Infancy a Myth? 总被引：4，自引：0，他引：4
Rachel K. Clifton Darwin W. Muir Daniel H. Ashmead Marsha G. Clarkson 《Child development》1993,64(4):1099-1110
The issue examined was whether infants require sight of their hand when first beginning to reach for, contact, and grasp objects. 7 infants were repeatedly tested between 6 and 25 weeks of age. Each session consisted of 8 trials of objects presented in the light and 8 trials of glowing or sounding objects in complete darkness. Infants first contacted the object in both conditions at comparable ages (mean age for light, 12.3 weeks, and for dark, 11.9 weeks). Infants first grasped the object in the light at 16.0 weeks and in the dark at 14.7 weeks, a nonsignificant difference. Once contact was observed, infants continued to touch and grasp the objects in both light and dark throughout all sessions. Because infants could not see their hand or arm in the dark, their early success in contacting the glowing and sounding objects indicates that proprioceptive cues, not sight of the limb, guided their early reaching. Reaching in the light developed in parallel with reaching in the dark, suggesting that visual guidance of the hand is not necessary to achieve object contact either at the onset of successful reaching or in the succeeding weeks. 相似文献
2.
Two-year-olds' (N = 153) knowledge of solidity was tested in four search tasks adapted from infant looking-time experiments. In Experiment 1, 2-year-olds failed to search in the correct location for a falling ball after a hidden shelf that blocked its trajectory had been inserted in the apparatus. Experiment 2 extended this finding by showing that 2-year-olds failed to take into account the effects of either removing or inserting a shelf in their search for a toy dropped behind a screen. Experiment 3 examined sensitivity to the constraint provided by a solid barrier on horizontal motion. In all three experiments, 2-year-old children searched initially at the location where they saw the object during familiarization. Experiment 4, using multiple test trials but no familiarization to a pretest location, also showed that 2-year-olds failed to take the presence or absence of a barrier into account when planning where to search for a toy they had seen dropped behind a screen. In all of these studies, 2-year-olds showed no evidence of representing solidity and support constraints on the trajectories of falling objects. Experiments 1 and 3 also included 2 1/2-year-olds (N = 31), who succeeded on these search tasks. The implications of the poor performance of 2-year-olds, in the face of success by very young infants on looking-time measures of sensitivity to similar constraints on object motion, are discussed. 相似文献
3.
Eisbach AO 《Child development》2004,75(6):1694-1707
This research explored the development of one insight about the mind, namely, the belief that people's trains of thought differ even when they see the same stimulus. In Study 1, 5-year-olds, 9-year-olds, and adults heard stories about characters who saw the same object. Although the older groups predicted the object would trigger different trains of thought, most 5-year-olds did not. In Study 2, 5-year-olds (preschoolers and kindergartners) and 7-year-olds heard similar stories, plus stories with additional individuating information about each character. With age, children increasingly recognized that thoughts would differ and could explain why. The development of this insight during the school years likely provides children with a more complete understanding of what it means to be a unique individual. 相似文献
4.
2 experiments examined children's understanding of the expression of speaker certainty and uncertainty and its relation to their developing theory of mind. In the first experiment, 80 children between 3 and 6 years of age were presented with a task in which they had to guess the location of an object hidden in 1 of 2 boxes. As clues to location, the children were presented with contrasting pairs of statements by 2 puppets. Different trials contained all of the possible pairwise combinations of either the modal verbs must, might, and could or the modal adjuncts probably, possibly, and maybe. Results showed that while 3-year-olds did not differentiate between any of the modal contrasts presented, 4-year-olds and older children were able to find the hidden object on the basis of what they heard. Performance was best for contrasts involving a highly certain term (either must or probably) paired with a less certain term (might, could, possibly, and maybe). Experiment 2 was designed to determine whether competence with modal terms was related to competence with mental terms in the same task, and whether performance on the certainty task was related to other aspects of the child's understanding of the nature of beliefs. 26 4-year-olds were presented with the certainty task, involving both modal and mental terms, and with tasks assessing their understanding of false beliefs, representational change, and the appearance-reality distinction. Results showed that all of these tasks were intercorrelated, implying that what may develop at 4 years of age may be a general understanding of the representational nature of belief. 相似文献
5.
To use a symbol to solve a problem, children must achieve representational insight; they must realize that the symbol stands for its referent. Moreover, they must keep this relation in mind as they attempt to use the symbol. The present studies investigated the achievement and maintenance of representational insight. 3-year-olds were asked to use a scale model of a room to find a toy hidden in the room. In Study 1a, children first watched as a small toy was hidden in the model. They then waited either 20 sec, 2 min, or 5 min before attempting to find a similar, larger toy that was hidden in the corresponding place in the room. All children experienced all delay intervals; three groups experienced the delays in different orders. There was a dramatic effect of delay order. The children who experienced the 20-sec delay on their first trial generally performed well throughout the 6 trials, but the children who experienced a 5-min delay first almost always failed to find the toy in the room, even on subsequent trials with shorter delays. Additional studies revealed that the negative effects of the initial long delay could be overcome by providing reminders of the model and its relevance (Studies 2 and 3) or by giving children prior experience in using the model (Study 4). The results indicate that keeping a symbol-referent relation in mind can be difficult for 3.0-year-old children. This research is discussed in terms of the importance of maintaining representational insight. 相似文献
6.
Children's suggestibility in relation to their understanding about sources of knowledge 总被引：1，自引：0，他引：1
In the experiments reported here, children chose either to maintain their initial belief about an object's identity or to accept the experimenter's contradicting suggestion. Both 3- to 4-year-olds and 4- to 5-year-olds were good at accepting the suggestion only when the experimenter was better informed than they were (implicit source monitoring). They were less accurate at recalling both their own and the experimenter's information access (explicit recall of experience), though they performed well above chance. Children were least accurate at reporting whether their final belief was based on what they were told or on what they experienced directly (explicit source monitoring). Contrasting results emerged when children decided between contradictory suggestions from two differentially informed adults: Three- to 4-year-olds were more accurate at reporting the knowledge source of the adult they believed than at deciding which suggestion was reliable. Decision making in this observation task may require reflective understanding akin to that required for explicit source judgments when the child participates in the task. 相似文献
7.
Young children often fail to generalize a novel verb based on sameness of action since they have difficulty focusing on the relational similarity across events while at the same time ignoring the objects that are involved. Study 1, with Japanese-speaking 3- and 4-year-olds (N = 28 in each group), found that similarity of objects involved in action events plays a scaffolding role in children's extraction of relational similarity across events when they extend a verb. Study 2, with 4-year-olds (N = 47), further showed that repeated experience of action-based verb extension supported by object similarity leads children to be better able to extend a novel verb based on sameness of action, even without support from object similarity. 相似文献
8.
Self-Recognition in Young Children Using Delayed versus Live Feedback: Evidence of a Developmental Asynchrony 总被引：3，自引：0，他引：3
The ability of young children to recognize themselves in delayed videotapes and recent photographs was investigated using a delayed analog of the mirror mark test, as well as verbal reports. In Experiment 1, 42 2–4-year-old children were videotaped while playing an unusual game. During the game an experimenter covertly placed a large sticker on the child's head. The videotape was played back 3 min later to the children. Older, but not younger, children reached up to remove the sticker when the tape revealed it being placed on their heads. In Experiment 2, a similar procedure was used with 60 3- and 4-year-olds where Polaroid photographs were taken during and after the act of the sticker being placed on the child's head. When allowed to look at the photographs, young 3-year-olds did not reach up to search for the sticker, whereas older 3- and 4-year-olds did. Almost all of the children who did not appear to realize that there was a sticker on their head from the information provided by the photographs did provide a correct verbal label for the image, and reached up to remove the sticker when presented with a mirror. Experiment 3 compared the reaction of 48 21/2–31/2-year-olds to live versus delayed video feedback and indicated an effect of the temporal aspect of the stimulus. The results are discussed in the context of the different forms of self-conception that may underwrite the 2 manifestations of self-recognition. 相似文献
9.
2 experiments on the development of the understanding of random phenomena are reported. Of interest was whether children understand the characteristic uncertainty in the physical nature of random phenomena as well as the unpredictability of outcomes. Children were asked, for both a random and a determined phenomenon, whether they knew what its next outcome would be and why. In Experiment 1, 4-, 5-, and 7-year-olds correctly differentiated their responses to the question of outcome predictability; the 2 older groups also mentioned appropriate characteristics of the random mechanism in explaining why they did not know what its outcome would be. Although 3-year-olds did not differentiate the random and determined phenomena, neither did they treat both phenomena as predictable. This latter result is inconsistent with Piaget and Inhelder's characterization of an early stage of development. Experiment 2 was designed to control for the possibility that children in Experiment 1 learned how to respond on the basis of pretest experience with the 2 different phenomena. 5- and 7-year-olds performed at a comparable level to the same-aged children in Experiment 1. Results suggest an earlier understanding of random phenomena than previously has been reported and support results in the literature indicating an early understanding of causality. 相似文献
10.
When utterances contain conflicting emotion cues, 6-year-olds judge emotion from content, even when instructed to judge emotion from paralanguage (Morton & Trehub, 2001). Two experiments examined the nature of this bias. In Experiment 1, priming paralanguage reversed 6-year-olds' normal bias to content. In Experiment 2, 6-year-olds were instructed to listen to paralanguage under various conditions. Children were more likely to follow instructions delivered with feedback than instructions delivered alone. Children who described conflicts between content and paralanguage were more likely to follow instructions than children who did not describe these conflicts. Results suggest that 6-year-olds can judge emotion from paralanguage in the presence of competing content but often remain focused on content because of the way they represent the instructions. 相似文献
11.
Effects of maternal interference on social behavior toward mother and exploratory play were examined in a laboratory experimental paradigm. Subjects were 40 1-year-olds and their mothers. Mothers of the 20 interference-group infants were instructed periodically to physically interfere with their child's independent object play during the first half of the observation session. A postinterference free-play period immediately followed. The 20 control-group infants were permitted by mother to play freely throughout the session. Groups were matched for exposure to play materials. Despite its aversiveness, interference had no subsequent effect on infant social initiatives to mother, responsiveness to mother's social bids, or exploratory play. 相似文献
12.
The ability to recall and organize actions was studied in children from 5 to 11 years in age. 8 different auditory or visual commands were successively presented for 10 trials in each modality in a free-recall task. Younger children performed fewer commands but recalled relatively more recent ones, and they showed the same degree of subjective organization and the same degree and structure of hierarchical clustering as the older children. The hierarchical structure was independent of recall, age, and modality, with the motor actions being organized by the locus of the object or instrument of the verb in the command. The difficulty of the commands was highly correlated with uncertainty of the locus of the action, that is, the number of possible arguments (objects or instruments) a verb could assume, as measured by a subsidiary experiment on 8-year-olds who were asked to name as many parts of the body upon or with which one could perform each action. Developmental differences in recall appear to rise because of primary organization (retrieval) and rehearsal strategies rather than secondary organization. 相似文献
13.
Children's perception of gap affordances: bicycling across traffic-filled intersections in an immersive virtual environment 总被引：1，自引：0，他引：1
This study examined gap choices and crossing behavior in children and adults using an immersive, interactive bicycling simulator. Ten- and 12-year-olds and adults rode a bicycle mounted on a stationary trainer through a virtual environment consisting of a street with 6 intersections. Participants faced continuous cross traffic traveling at 25 mph or 35 mph and waited for gaps they judged were adequate for crossing. Children and adults chose the same size temporal gaps, but children left far less time to spare between themselves and the approaching vehicle when they crossed the intersection. Relative to adults, children delayed in getting started and took longer to reach the roadway. Discussion focuses on developmental changes in how children coordinate self movement with object movement. 相似文献
14.
The effect of active exploration upon memory for spatial location of an event was assessed for children at 2 age levels. Each child took a walk through the same unfamiliar hallway in search of a hidden object which he was later asked to relocate. Half the children were accompanied by an adult holding their hand (passive condition), while the other half proceeded on their own with an adult following behind (active condition). An age x condition interaction revealed that active exploration significantly improved performance of the 3- and 4-year-old group while not affecting the performance of the 9- and 10-year-olds. The 3- and 4-year-olds in the active condition, however, were still significantly less accurate than the older children, despite their experience of self-directed exploration. The results are interpreted as supporting the hypothesis that self-directed activity serves to increase attention of preoperational children to relevant topological cues in the environment, whereas concrete operational children, due to their knowledge of projective and Euclidean space, demonstrate increased capacity to efficiently encode spatial information regardless of the mode of exploration. 相似文献
15.
Daniel H. Ashmead Michael E. McCarty Linda S. Lucas Mariana C. Belvedere 《Child development》1993,64(4):1111-1127
This experiment evaluated the role of visual input about the location of a target object and the location of the hand in reaching by infants and adults. 5- and 9-month-old infants were presented with illuminated toys to reach for in a dark room. On no-switch trials, the toy remained illuminated throughout the infant's reach, whereas on switch trials the first-lit toy was replaced during the reach by a second-lit toy at a different position. On approximately half of the trials of each type a luminescent marker was attached to the reaching hand. Adult subjects (tested without the hand marker) fully compensated to the second-lit toy on switch trials, during a second reaching segment. On switch trials, 9-month-olds partially adjusted to the second-lit toy when wearing the hand marker and did not adjust without it. On no-switch trials, 9-month-olds reached just as accurately with or without the hand marker. 5-month-olds were generally inaccurate in their reaching and were unaffected by the presence or absence of the hand marker. The findings suggest that during the development of reaching there is an increase in visual guidance during the approach phase of reaches. 相似文献
16.
Inability of five-month-old infants to retrieve a contiguous object: a failure of conceptual understanding or of control of action? 总被引：2，自引：0，他引：2
Infants of 5 to 6 months of age can retrieve a free-standing object, but fail to retrieve the same object from atop a slightly larger object. The accepted explanation has been that the infants do not understand that an object continues to exist independently when placed upon another. Predictions based on that explanation were tested against the hypothesis that infants' problem consists of lack of precision in visually guided reaching and lack of ability to inhibit reflexive reactions to touch. Twelve infants each at 5 and 7 months of age were tested on 16 trials. More 5-month-olds succeeded, in less time, and with fewer touches to an edge of the base, on trials more forgiving of an imprecise reach than on less forgiving trials. Success in retrieving objects close in size and fully contiguous with their bases was seen even at 5 months when the demands on skill in reaching were reduced. It is proposed that when 5-month-old infants fail to retrieve one object placed upon another, it is not because of a lack of conceptual understanding, but because they lack the skill to reach to the top object without accidentally touching an edge of the base en route. 相似文献
17.
The ability of infants aged 8–12 months to coordinate their arm and trunk movements to contact an object located in different positions was investigated in 2 experiments. In the first, 8- and 10-month-old infants reached for near objects but both reached and leaned for more distant ones indicating that they perceived that forward leaning extends the range of contact beyond that of reaching alone. In addition, arm and trunk movements were initiated simultaneously; visual information concerning object distance was sufficient to activate an integrated reaching-and-leaning response. Object distances were increased and a mechanical aid was provided on half the trials in the second experiment with 10- and 12-month-old infants. For both age groups the degree of leaning was reduced for objects that were out of reach without the aid. Only older infants were able to use the aid to extend partially their range of contact. Overall the results support the conclusions that, by at least 8 months, infants perceive that leaning extends their effective reaching space; by 10 months they perceive the limits within which reaching together with leaning is likely to be effective; and by 12 months they begin to perceive how this space may be extended by a mechanical aid. 相似文献
18.
Preschoolers' Reasoning about Density: Will It Float? 总被引：1，自引：0，他引：1
Amy S. Kohn 《Child development》1993,64(6):1637-1650
Density is a complex concept found to appear late in development. However, density has a readily apparent empirical consequence—buoyancy. Early scientific understanding of density arose through Archimedes' discovery of water displacement as a function of density, and young children have experience playing with objects in water. Therefore, a buoyancy prediction task was developed in order to access preschoolers' early understanding of density. 3–5-yearold children from 2 preschool classes, as well as adults, made buoyancy predictions for a set of objects that varied systematically in density, weight, and volume. 4–5-year-olds (from the older class) and adults were shown to demonstrate similar patterns in their judgments. Objects much more or much less dense than water were more accurately judged than objects with densities closer to the density of water. Weight and volume were found to "interfere" in these judgments in systematic ways for the older class of children and the adults. Children in the younger class (3-year-olds) showed a mean proportion correct performance of .53; they all passed a pretest, however, and no child refused to make judgments. 相似文献
19.
Trait Understanding or Evaluative Reasoning? An Analysis of Children''s Behavioral Predictions 总被引：3，自引：0，他引：3
This study tested the hypothesis that in predicting the future behavior of an actor, older children rely on trait inferences, whereas younger children rely on global, evaluative inferences. Vignettes depicting actors engaging in trait-relevant behaviors were presented to 5- and 6-year-olds (N = 67) and 9- and 10-year-olds (N = 71). For each actor, children made predictions of future behavior, evaluated the goodness and badness of the actor, and rated each actor on a relevant trait. A mediational analysis found that the behavioral predictions of older children were mediated solely by trait ratings, whereas those of younger children were mediated by evaluative ratings. Furthermore, unlike older children, younger children made trait-like predictions only when they made an evaluation of the actor. These results suggest that young children utilize evaluative reasoning when making behavioral predictions, and therefore rely on an inferential process that is distinct from that of older children. 相似文献
20.
D A Baldwin 《Child development》1989,60(6):1291-1306
Young children show considerable interest in color similarity; thus we might expect them to use color as a basis for generalizing object labels. However, natural language observations suggest they do not: children tend to overextend labels based on form similarity and rarely, if ever, overextend labels to objects that share only color. Perhaps, then, children give form priority over color in their expectations about object-label reference. This hypothesis was investigated in 2 studies. In a first study, 40 2- and 3-year-olds sorted 10 sets of 3 pictures that contrasted form with color. Children participated in 1 of 2 conditions: half of the children were shown a target object and asked to "find another one" from among the two choice objects, while the other children heard a novel label for the target (e.g., "See this zom?") and were asked to extend the label (e.g., "Can you find another zom?"). 3-year-olds sorted almost exclusively on the basis of form in both conditions, while 2-year-olds performed differently in the 2 conditions: they frequently chose the color match when labels were absent, but selected by form rather than color when asked to extend a novel label. A second study replicated these findings with novel objects that were real rather than pictured. This study also suggested that 3-year-olds grant color some role in their decisions about object-label reference as long as form differences are reduced to a tolerable level. In sum, young children expect form to be more important than color for guiding object-label reference, even though they may find color interesting when not asked to extend labels. This expectation helps explain the speed and relative ease with which children acquire object labels. 相似文献